<div>
  <nz-row [nzGutter]="40">
    <nz-col [nzSpan]="12">
      <div id="chart1" style="margin: 0 auto; height: 400px; width: 100%"></div>
    </nz-col>
    <nz-col [nzSpan]="12">
      <div id="chart2" style="margin: 0 auto; height: 400px; width: 100%"></div>
    </nz-col>
  </nz-row>
</div>
